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There is a 3 bit field in the Layer 2 802.1q frame header which is used to carry the CoS QoS marking • A value of 0 - 7 can be set. The default value is 0 which is designated as Best Effort traffic • CoS 6 and 7 are reserved for network use • IP phones mark their call signalling traffic as CoS 3 and their voice payload as CoS 5 FLACKBOX www.flackbox.com III

Diffsurv The ToS Type of Service byte in the Layer 3 IP header is used to carry the DSCP QoS marking 6 bits are used which gives 64 possible values. The default value is 0 which is designated as Best Effort traffic • IP phones mark their call signalling traffic as 24 (CS3) and their voice payload as 46 (EF) There are standard markings for other traffic types, such as 26 (AF31) for mission critical data, and 34 (AF41) for SD video

Access Control List can be used to recognise traffic based on its Layer 3 and Layer 4 information For example SSH traffic going to and from the router 10.10.100.10 on TCP port number 22 NBAR (Network Based Application Recognition) can be used to recognise traffic based on its Layer 3 to Layer 7 information • Signatures can be downloaded from Cisco and loaded on your router which recognise well known applications

Voice and traditional standard definition video packets must meet these recommended requirements to be an acceptable quality call: Latency (delay) < 150 ms Jitter (variation in delay) < 30 ms Loss < 1% These are one way requirements, meaning a packet sent from a phone in HQ has 150ms to reach the phone in the branch, and vice versa • HD video has stricter requirements

Traffic Shaping and Policing can be used to control traffic rate. They both measure the rate of traffic through an interface and take an action if the rate is above a configured limit. • Traffic shaping buffers any excess traffic so the overall traffic stays within the desired rate limit. • Traffic policing drops or re-marks excess traffic to enforce the specified rate limit. Classification can be used to allow different rates for different traffic types.

Virtual routing and forwarding, Only high and rounders can virtualize routers. So Instead you can use VFR which separates the routing tables so to separate customers can be on the same router.